m-Chloroperbenzoic acid → (+/-)-6-(3-Methoxy-phenyl)-7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester

Participants

Reaction Steps

4-(3-Methoxy-phenyl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (2 g, 6.9 mmol) was further purified by flash chromatography (100 DCM on Silicagel) to remove baseline impurities (likely waste palladium from Suzuki reaction), then was dissolved in methylene chloride (28.9 mL, 451 mmol) and treated with m-CPBA 70-75% (70:30, m-chloroperbenzoic acid: 3-chlorobenzoic acid, 2.4 g, 9.7 mmol) at room temperature overnight. The reaction was quenched by treatment with a Na2S2O3 aq solution, followed by sat. NaHCO3 aq. solution, and further extracted twice with dichloromethane. The combined organic extracts were dried (MgSO4) and filtered, and the solvent was evaporated under reduce pressure. The product was used without further purification in the next step: (±)-6-(3-methoxy-phenyl)-7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester (2 g, 95% yield). 1H NMR (CDCl3): δ ppm 7.26 (m, 1H), 6.95 (d, J=7.8 Hz, 1H), 6.90 (br. s., 1H), 6.84 (d, J=8.1 Hz, 1H), 3.93-4.19 (m, 1H), 3.81 (s, 3H), 3.53-3.79 (m, 2H), 3.10-3.24 (m, 2H), 2.38-2.51 (m, 1H), 2.17 (br. s., 1H), 1.48 (s, 9H).

Provenance & Evidence